While growing microgreens is relatively simple when compared to a lot of hydroponic plants, you can still run into a lot of different problems. In the microgreens business that I have recently started, I’ve found that it’s been a challenge to control for all of the different things that can go wrong when growing restaurant-ready microgreens.
Here are all of the microgreen problems I have run into, along with how to solve them!
Mold or Fungus
This is one of the biggest problems I’ve run into due to my 70 degree + summer temperature and high humidity the past few months. There is a BIG difference between mold and root hairs, which are concentrated around the main root of the seed and are very beneficial for a plant at the beginning of its life.
You will find that white mold looks like a spiderweb crawling across the surface of the growing media. It starts out in one area in a small, wispy ball and then expands quickly over the growing media. If you don’t take care of it, pretty soon it will climb up the stems of your plants and your entire crop is ruined.
The Solution
- Make sure your trays are CLEAN before you plant
- Decrease humidity by increasing air circulation (hard in the blackout period but you can partially uncover the trays)
- Decrease the seed density of your future trays, especially for mucilaginous seeds
- Try using Grapefruit Seed Extract mixed with water as an organic solution
Slow Germination
Most microgreen seeds germinate within 2-4 days, but some take a bit longer. If you’re seeing much longer germination times, something is wrong.
The Solution:
- Increase moisture in the tray by spraying more / more often
- Do a germination test with some of your seed in a wet paper towel
Yellowish Microgreens
This isn’t a very common problem, but it can happen sometime. Before you take the blackout dome off of your microgreen trays, all of your seedlings will be yellow. This is because they have not been able to take in light and start the process of photosynthesis.
The Solution:
- Take the blackout dome off of the trays earlier
- Place trays near a stronger light source
Clumpy Microgreens
When you’re spreading your seed out in trays, it can be difficult to get an even spread. Sometimes if you plant seeds too densely they will clump together, especially if they’re mucilaginous. When they sprout, a few of the seedlings will “push” the rest of them up into the air, suspending the roots and possibly bringing dirt along with them. This makes it very hard to harvest.
The Solution:
- Decrease total seed volume planted per tray
- Spread seeds more evenly throughout the tray
Weak Looking Microgreens
This is an all encompassing condition that covers the rest of the problems that you’ll have. It’s hard to troubleshoot exactly why a particular microgreen crop is doing poorly if you’ve already made sure you don’t have any of the conditions above.
In my case, a lot of the weakness I saw in my crops was due to a lack of moisture control – either too dry or too wet. In some cases I didn’t properly prepare the seed before planting it, and in others I took the blackout dome off too earlier or too late.
The Solution:
- Be very sure to read the seed packets very carefully to see what you need to do for each type of microgreen
- Stick to a normal watering and misting schedule
- Different crops need the blackout dome taken off at different times – be sure to be crop-specific
- Some crops need the blackout dome flipped upside down on top of them to make them “struggle” to thrive
That should cover most of the problems you’ll have with microgreens. I’ll be talking more about them in the future, but in the meantime you can take a look at the main microgreens page to see what aspects of growing microgreens I’ve already covered.
